1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Cache Allocation Technology (CAT) test
4 *
5 * Copyright (C) 2018 Intel Corporation
6 *
7 * Authors:
8 *    Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>,
9 *    Fenghua Yu <fenghua.yu@intel.com>
10 */
11#include "resctrl.h"
12#include <unistd.h>
13
14#define RESULT_FILE_NAME1	"result_cat1"
15#define RESULT_FILE_NAME2	"result_cat2"
16#define NUM_OF_RUNS		5
17#define MAX_DIFF_PERCENT	4
18#define MAX_DIFF		1000000
19
20/*
21 * Change schemata. Write schemata to specified
22 * con_mon grp, mon_grp in resctrl FS.
23 * Run 5 times in order to get average values.
24 */
25static int cat_setup(struct resctrl_val_param *p)
26{
27	char schemata[64];
28	int ret = 0;
29
30	/* Run NUM_OF_RUNS times */
31	if (p->num_of_runs >= NUM_OF_RUNS)
32		return END_OF_TESTS;
33
34	if (p->num_of_runs == 0) {
35		sprintf(schemata, "%lx", p->mask);
36		ret = write_schemata(p->ctrlgrp, schemata, p->cpu_no,
37				     p->resctrl_val);
38	}
39	p->num_of_runs++;
40
41	return ret;
42}
43
44static int check_results(struct resctrl_val_param *param, size_t span)
45{
46	char *token_array[8], temp[512];
47	unsigned long sum_llc_perf_miss = 0;
48	int runs = 0, no_of_bits = 0;
49	FILE *fp;
50
51	ksft_print_msg("Checking for pass/fail\n");
52	fp = fopen(param->filename, "r");
53	if (!fp) {
54		perror("# Cannot open file");
55
56		return errno;
57	}
58
59	while (fgets(temp, sizeof(temp), fp)) {
60		char *token = strtok(temp, ":\t");
61		int fields = 0;
62
63		while (token) {
64			token_array[fields++] = token;
65			token = strtok(NULL, ":\t");
66		}
67		/*
68		 * Discard the first value which is inaccurate due to monitoring
69		 * setup transition phase.
70		 */
71		if (runs > 0)
72			sum_llc_perf_miss += strtoul(token_array[3], NULL, 0);
73		runs++;
74	}
75
76	fclose(fp);
77	no_of_bits = count_bits(param->mask);
78
79	return show_cache_info(sum_llc_perf_miss, no_of_bits, span / 64,
80			       MAX_DIFF, MAX_DIFF_PERCENT, runs - 1,
81			       get_vendor() == ARCH_INTEL, false);
82}
83
84void cat_test_cleanup(void)
85{
86	remove(RESULT_FILE_NAME1);
87	remove(RESULT_FILE_NAME2);
88}
89
90int cat_perf_miss_val(int cpu_no, int n, char *cache_type)
91{
92	unsigned long l_mask, l_mask_1;
93	int ret, pipefd[2], sibling_cpu_no;
94	unsigned long cache_size = 0;
95	unsigned long long_mask;
96	char cbm_mask[256];
97	int count_of_bits;
98	char pipe_message;
99	size_t span;
100
101	/* Get default cbm mask for L3/L2 cache */
102	ret = get_cbm_mask(cache_type, cbm_mask);
103	if (ret)
104		return ret;
105
106	long_mask = strtoul(cbm_mask, NULL, 16);
107
108	/* Get L3/L2 cache size */
109	ret = get_cache_size(cpu_no, cache_type, &cache_size);
110	if (ret)
111		return ret;
112	ksft_print_msg("Cache size :%lu\n", cache_size);
113
114	/* Get max number of bits from default-cabm mask */
115	count_of_bits = count_bits(long_mask);
116
117	if (!n)
118		n = count_of_bits / 2;
119
120	if (n > count_of_bits - 1) {
121		ksft_print_msg("Invalid input value for no_of_bits n!\n");
122		ksft_print_msg("Please enter value in range 1 to %d\n",
123			       count_of_bits - 1);
124		return -1;
125	}
126
127	/* Get core id from same socket for running another thread */
128	sibling_cpu_no = get_core_sibling(cpu_no);
129	if (sibling_cpu_no < 0)
130		return -1;
131
132	struct resctrl_val_param param = {
133		.resctrl_val	= CAT_STR,
134		.cpu_no		= cpu_no,
135		.setup		= cat_setup,
136	};
137
138	l_mask = long_mask >> n;
139	l_mask_1 = ~l_mask & long_mask;
140
141	/* Set param values for parent thread which will be allocated bitmask
142	 * with (max_bits - n) bits
143	 */
144	span = cache_size * (count_of_bits - n) / count_of_bits;
145	strcpy(param.ctrlgrp, "c2");
146	strcpy(param.mongrp, "m2");
147	strcpy(param.filename, RESULT_FILE_NAME2);
148	param.mask = l_mask;
149	param.num_of_runs = 0;
150
151	if (pipe(pipefd)) {
152		perror("# Unable to create pipe");
153		return errno;
154	}
155
156	fflush(stdout);
157	bm_pid = fork();
158
159	/* Set param values for child thread which will be allocated bitmask
160	 * with n bits
161	 */
162	if (bm_pid == 0) {
163		param.mask = l_mask_1;
164		strcpy(param.ctrlgrp, "c1");
165		strcpy(param.mongrp, "m1");
166		span = cache_size * n / count_of_bits;
167		strcpy(param.filename, RESULT_FILE_NAME1);
168		param.num_of_runs = 0;
169		param.cpu_no = sibling_cpu_no;
170	}
171
172	remove(param.filename);
173
174	ret = cat_val(&param, span);
175	if (ret == 0)
176		ret = check_results(&param, span);
177
178	if (bm_pid == 0) {
179		/* Tell parent that child is ready */
180		close(pipefd[0]);
181		pipe_message = 1;
182		if (write(pipefd[1], &pipe_message, sizeof(pipe_message)) <
183		    sizeof(pipe_message))
184			/*
185			 * Just print the error message.
186			 * Let while(1) run and wait for itself to be killed.
187			 */
188			perror("# failed signaling parent process");
189
190		close(pipefd[1]);
191		while (1)
192			;
193	} else {
194		/* Parent waits for child to be ready. */
195		close(pipefd[1]);
196		pipe_message = 0;
197		while (pipe_message != 1) {
198			if (read(pipefd[0], &pipe_message,
199				 sizeof(pipe_message)) < sizeof(pipe_message)) {
200				perror("# failed reading from child process");
201				break;
202			}
203		}
204		close(pipefd[0]);
205		kill(bm_pid, SIGKILL);
206	}
207
208	cat_test_cleanup();
209
210	return ret;
211}
212